The discovery comes as the Taliban have stepped up their attacks in Afghanistan and U.S.-led foreign forces are reducing their presence in the country. The handover of responsibility for security to local forces has made the Afghan army an even more tempting target than usual for militants.

Local residents found the corpses next to each other in Andar district of Ghazni province, their hands chained behind their backs. The dead soldiers had been kidnapped at different times, with some abducted while they were on leave visiting relatives, said Mohammad Ali Ahmadi, deputy Ghazni governor. The victims hailed from northern provinces and were found with identification documents.

The Taliban did not issue a claim of responsibility for the killings, but Ahmadi said the insurgents are known to occasionally stop vehicles in search of people to “prosecute” for working for the U.S.-supported Afghan government or security forces.

In Ghazni’s Qarabagh district, two Afghans involved in civilian militias that resist the Taliban were killed during a gunfight with militants, Ahmadi said. Such citizen militias have cropped up in several parts of Afghanistan.

Meanwhile, a roadside bomb killed eight Afghan employees of a private mining company in the north on Saturday, authorities said. The workers were traveling in a small truck to the chromite mine in the Bagram district of Parwan province. Provincial governor Abdul Basir Salangi said Sunday that five people also were wounded in the explosion, and that the victims were all either laborers or security guards of the company.

An explosion on Sunday, meanwhile, apparently targeted the mayor of the eastern city of Jalalabad, but wounded his driver instead.

Hazrat Hussain Mashreqiwal, a police spokesman in Nangarhar province, said the mayor was not in the vehicle when the bomb went off, and that investigators are trying to determine the type of bomb used.